Dental X-Rays: Types, Frequency and Radiation Safety
Dental X-rays (radiographs) let a dentist see decay, roots and bone that a visual examination may miss. This page covers the main types, why UK law requires every X-ray to be clinically justified, why there is no fixed schedule, how doses compare with background radiation, and guidance on pregnancy and children, then Deepcar Dental Care's imaging equipment and fees.
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Clinically reviewed by Dr Ibraheem Ijaz, dentist · GDC 301711
Medical disclaimer: This page is for general information only. It does not replace an examination or treatment by a dentist.
This page is reviewed by Dr Ibraheem Ijaz, the practice's principal dentist and a General Dental Practitioner (GDC 301711). His qualifications are BDS, BSc (Hons), MSc (Leeds), PG Dip Implant Dentistry and PG Cert Restorative and Aesthetic Dentistry.
What are dental X-rays?
Dental X-rays are images made with ionising radiation that show parts of the teeth and jaw a dentist cannot see directly. They can show the roots below the gum, the bone around them and decay that would otherwise stay hidden; our page on enamel, dentine and pulp explains how a tooth is built.
Why are dental X-rays taken?
Dental X-rays are taken to help diagnose a problem, plan treatment or check how treatment is healing. Faculty of General Dental Practice (UK) (FGDP) guidance calls an X-ray useful when its result, positive or negative, will change or add confidence to the diagnosis or treatment plan. Our page on a hole in a tooth explains what happens once decay has made a cavity.
Must every dental X-ray be clinically justified?
Yes. In UK law and guidance, every dental X-ray must be clinically justified before it is taken, meaning its expected benefit to you outweighs the radiation risk.
In Great Britain the law is the Ionising Radiation (Medical Exposure) Regulations 2017, known as IR(ME)R or IRMER; Northern Ireland has its own 2018 regulations. Department of Health and Social Care guidance says any exposure must be justified before it can take place, and that the practitioner is responsible for justifying each individual exposure. Justification weighs the diagnostic benefits against the detriment for that person, and considers whether a technique using less or no ionising radiation could answer the clinical question.
The FGDP selection criteria for dental radiography say the choice of X-ray should be based on the individual patient's history and a clinical examination. The routine use of X-rays based on a generalised approach rather than individual prescription is, in their words, unacceptable.
What types of dental X-ray are there?
Dental X-rays are either intraoral, with the detector inside the mouth, or extraoral, with the detector outside it. The main types are:
- Bitewing X-rays: intraoral views of the back teeth.
- Periapical X-rays: intraoral views that include the roots.
- Panoramic X-rays (OPG, short for orthopantomogram): extraoral, wide-angled views of the jaws and teeth.
- Cone beam CT (CBCT): extraoral, three-dimensional scans of the teeth and jaws.
What does each type of dental X-ray show?
Each type of dental X-ray answers a different clinical question, and UK guidance aims for the view that answers yours at the lowest dose.
Bitewing X-rays
FGDP guidance makes the same decay recommendations for adults as for children, while suggesting that high-quality studies with adults are needed. It calls posterior bitewings an essential adjunct to the clinical examination: necessary for detecting decay between the teeth, they can also offer a significant yield in detecting biting-surface decay. When already taken for decay, they give information about bone levels without an extra radiation dose.
Periapical X-rays
Periapical X-rays show one area in detail, including the roots and the tissues around them. FGDP guidance says at least one is necessary before root canal treatment to help diagnosis, and that X-rays are an essential aid in following up healing after it.
Panoramic X-rays (OPG)
A panoramic X-ray is a wide-angled image of the jaws and teeth that also shows an image of the mandibular condyles, part of the jaw joints. FGDP selection criteria for one include a bony lesion or unerupted tooth too large or awkwardly placed to show fully on intraoral X-rays, and assessing wisdom teeth before planned surgery. The guidance says panoramic X-rays should not be seen as a routine technique for general dental practice, and notes a study in which they gave little or no information that influenced diagnosis or management of jaw joint symptoms in most cases examined.
Cone beam CT (CBCT)
A CBCT scan produces high-resolution, three-dimensional images of the teeth and jaws. FGDP guidance lists uses including root canal treatment and assessing the jaw before implant placement. How a scan is used to plan implants is covered on our page about CBCT scanning for implant planning.
Questions about this treatment? Book online or call the practice.
How often are dental X-rays needed?
There is no fixed timetable: in UK guidance, how often you need dental X-rays depends on your own history, examination and risk.
FGDP selection criteria say 'routine' X-rays based solely on time since the last examination are not supportable. For bitewings checking for decay, your assessed decay risk is central to deciding the interval, which must be reassessed each time because people can move in and out of risk groups. For gum (periodontal) X-rays, the guidance finds no clear evidence to support any recommended frequency. Panoramic X-rays should only be taken for specific clinical signs and symptoms, with no justification for repeating them at arbitrary intervals.
In FGDP guidance, each decision follows a history and clinical examination, such as at a dental check-up.
How much radiation does a dental X-ray give?
In UK Health Security Agency (UKHSA) figures, a typical single bitewing X-ray dose equals less than 1.5 days of natural background radiation.
| Examination (UKHSA wording) | Typical effective dose | Equivalent period of natural background radiation | Lifetime additional risk of fatal cancer per examination |
|---|---|---|---|
| Teeth (single bitewing) | less than 0.01 mSv | less than 1.5 days | 1 in a few million |
| Teeth (panoramic) | 0.01 mSv | 1.5 days | 1 in 2 million |
| Chest (single PA film) | 0.02 mSv | 3 days | 1 in a million |
| Skull | 0.07 mSv | 11 days | 1 in 300,000 |
| CT head | 2 mSv | 1 year | 1 in 10,000 |
Every row is from UKHSA's Patient dose information guidance, which bases background periods on a UK average of 2.1 mSv a year (regional averages 1.5 to 7.5 mSv). A millisievert (mSv) is one thousandth of a sievert, and FGDP guidance notes that dental doses are often small enough to give in microsieverts (µSv), one millionth of a sievert. UKHSA's risks are approximate lifetime figures for patients aged 16 to 69; UKHSA says to multiply them by about 2 for children and divide them by about 5 for older patients.
CBCT scans are not in the UKHSA table. FGDP guidance says the dose from a CBCT examination is comparable to between two days' and six months' additional background radiation, depending on the machine used and the exposure settings.
Are dental X-rays safe?
Dental X-rays carry a very small risk, which FGDP guidance places in the lowest risk category, but no dose is assumed to be risk-free.
FGDP guidance explains that the main risk is a small chance of cancer that may develop many years later, that there is no clear evidence of a safe level of radiation dose, and that the lower the dose, the lower the risk.
What does UK guidance say about dental X-rays in pregnancy?
FGDP guidance says there is no requirement to delay common dental X-rays until after the birth, but recommends offering the option of delaying non-urgent ones.
In FGDP's words, "it is unusual for an x-ray beam to be pointed at the abdomen (only for vertex occlusal radiographs, which are rarely indicated)", and where one is essential, abdominal lead protection should be used when a foetus lies in the primary beam. For all other dental views, "including panoramic and CBCT examinations, there is no requirement to delay radiography until after the birth." FGDP recommends offering that option because the subject is emotive.
NHS guidance is to tell the healthcare professional before an X-ray if you are pregnant or might be pregnant. Under IR(ME)R, where pregnancy cannot be excluded, particularly if the abdomen or pelvis is involved, the practitioner must have particular regard to the urgency of the exposure.
What does UK guidance say about dental X-rays for children?
FGDP guidance says radiation risk is highest for the young, so X-rays for children should use specific paediatric exposure protocols to minimise the dose.
Young children, FGDP guidance explains, are at about two to three times the risk of radiation-induced cancer of adults in their thirties for the same dose. It also says bitewing X-rays for decay should be considered even for pre-school children.
FGDP guidance gives a parent supporting a child during an X-ray as an example of a 'carer and comforter': the regulations suggest considering their dose, and gaining their informed consent, during justification.
When should you speak to your dentist about an X-ray?
NHS guidance is to tell the healthcare professional before an X-ray if you are or might be pregnant.
FGDP guidance aims to prevent X-rays that duplicate earlier ones, so recent dental X-rays taken elsewhere are worth mentioning, and a King's College Hospital NHS leaflet notes you can discuss how the information will help your diagnosis or treatment.
What imaging equipment does Deepcar Dental Care have?
Deepcar Dental Care's on-site equipment includes digital X-rays, an OPG machine, a CBCT scanner and 3D imaging. Our patient reviews show what patients say about the practice.
What does the Deepcar Dental Care fee list show for X-rays?
The current Deepcar Dental Care fee list includes a 'Small X-Ray' line from £15. Fees are starting prices that depend on individual clinical needs, and our general dentistry fees page shows what it costs for other general treatments.
Frequently asked questions
Can a panoramic X-ray replace bitewing X-rays?
Not for the most common problems. FGDP guidance says intraoral X-rays, such as bitewings and periapicals, are better than panoramic X-rays for diagnosing decay, gum disease and problems around the root tips. Where X-rays are clinically indicated, it says intraoral X-rays should be considered optimal because of better detail and lower radiation doses.
Are dental X-rays available on the NHS?
Yes, where clinically needed, at practices providing NHS care. In England, NHS guidance lists "X-rays, if clinically needed" in Band 1, currently £27.90, alongside an examination, assessment and advice. Free NHS dental treatment covers groups including under-18s, under-19s in full-time education, and anyone pregnant or who has had a baby in the last 12 months.
Why can the dose from the same type of X-ray differ?
Because equipment and technique differ. For intraoral X-rays, FGDP guidance says modern equipment, good technique and sensitive detectors can make a tenfold difference. Auditing patient doses against locally set diagnostic reference levels is a UK legal requirement, and doses above them must be investigated.
This page sits in the general dentistry treatments section: compare the options in this section, or for ongoing care of teeth and gums, read about our general dental services.
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We look after patients from Deepcar, Stocksbridge and Oughtibridge, and from across north Sheffield, including Wadsley, Hillsborough and Fulwood. Many travel further, from Penistone, Barnsley and Rotherham. The practice is on the A6102 at 334 Manchester Road, and no referral is needed.
334 Manchester Road
Deepcar, Sheffield S36 2RH
0114 288 2121
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